The invention relates to a tank ventilation system for a motor vehicle according to the preamble of patent claim 1.
Such a tank ventilation system is known from DE 196 50 517 C2. The hydrocarbons escaping from the tank are absorbed in an activated carbon filter. For regeneration of the activated carbon filter the absorbed hydrocarbons are aspirated into the intake duct at defined operating states of the internal combustion engine and supplied to the cylinder for combustion. In order to achieve a rinsing effect of the activated carbon filter an aeration line is provided which connects the activated carbon filter with the atmosphere when the aeration valve is open. The ventilation line usually exits at an outside of the motor vehicle.
In such known tank ventilation devices however the functioning may be impaired.